700 T-Rex 700E build

[pvolcko]

Got some more done.

- Ikon setup is complete, I believe. I have not setup auto-level yet.
- ESC connectors are soldered on. Made one goof, forgetting some heat shrink before putting a bullet in the EC5. Going to wrap in some electrical tape. I like having short shrink segments near the connector as a sort of strain relief and to cover up any soldering discoloration or other damage to the wire cladding. Also spliced in the take off lead to power the BEC. Screwed up and made the lead too short so had to cut that and splice in another segment.
- Motor and pinion, mounting block and lower bearing block are LT'd down.
- Tail servo setup done, horn adjusted and link ball reinstalled and backing nut LT'd down.
- Tail blades installed.

Remaining:

- Tail control link guides need to be set.
- Wire routing and zip ties.
- Sat rx's placed/mounted and leads routed.
- Mount the Ikon.
- Get batteries velcrod to plates, and strapped down.
- Recheck everything.

Then... maiden flight.

Stumbling block. Not enough velcro straps. And LHS doesn't have the length needed to secure these batteries. I'll see if I can scrounge up what I need here.

Weather tomorrow is supposed to be very windy, but Sunday or Monday are looking good. Tuesday is looking to be very nice. So Tuesday latest. I recently joined a local RC flight club and heli day is Tuesday so would be good to have it flying by then.

Question on Ikon setup: What cyclic deflection pitch should I set? I'm familiar with collective pitch (set to 12 deg). But not sure what to set cyclic too. For the moment I have it set to 10 deg. Nothing is binding at full extensions.

 

[coolgabsi]

Cyclic pitch is where you Put your blades parallel to the body, and at mid stick (zero degrees) , then add aileron. That's how much pitch will be added to your disc when a full cyclic input is given

I run 10 on whiplash . But it's a bit too fast sometimes. All that means is at full pitch and full collective , on half of your disc, you'll have 22defrees of blade deflection.

I suggest beginners to start with 8. That's more than enough. My nitro barely has 8 degrees of cyclic throw programmed.

If you set it too low then in flight the heli either would flip and roll at all or will be extremely slow.

8 is a great number. 10 is a little aggressive. You are a good flier, so it's your choice. Either ways, you can set your agility lower on the ikon (that's the beginner, sport , 3D and all) .. Where you can use thier numbers or use your own by increasing and decreasing as you would like



Now that I mentioned agility: it is the speed at which the ikon is gonna react to a stick movement and get the heli to the desired position.

That may involve some farther movement than programmed just to get the heli going faster in that direction and ikon backs it off a bit. It's just algorithms they got. Too much agility will make a bounce ... So when you are doing a tic toc say, at the two end stop posts, the heli instead of stopping at a tic will oscillate a bit... That's when it's too high


On the whiplash I had the agility at 90 and cyclic at 10 and collective at 12 .. And I didn't need any collective movement to make a full flip... It would just be so fast and loud that the heli would just sit there rolling on an axis as ikon was so fast and there was so much pitch. It was crazy. So I backed off agility a bit.

Fly safe!! have fun!

 

[pvolcko]

OKay. Cool. Sounds like I'm in the ball park, maybe a bit aggressive. I'll back the setting off a click or two which should put me right around 9. Assigned my gyro switch to the banks and have a basic, sport, and 3D default setup going in banks 1-3 respectively. Will see how it all behaves after test flight and start dialing things in. My actual gyro channel is on the Ail DR switch.

One more issue to work out. Getting the castle ESC all set. It's in heli mode, so fixed endpoints. I played with it on the table (blades off). The 100% position seems just right. I have the auto-rotation bailout feature on, so there are two levels of 0 throttle. I'm finding the auto-rotation bailout off threshold kicks in around 13% throttle and full-off/reset signal kicks in around 8% throttle. So I set my hold curve up around 10 or 11 percent (so bailout is available). Normal curve is linear 0-100. Idle up is currently 90% across (haven't played with gov settings yet). I also assigned a throttle cut to the trainer button which is set at full negative setting (beyond even the low setting for the Ikon's throttle mapping), as a sort of backup in case its needed.

That all sound right?

My issue is that there is a lot of throttle stick movement before it starts doing anything while in normal mode. Would it be safe/reasonable to move the lowest point in the normal throttle curve up to say 6%? Or perhaps use the trainer as reset button and actually have the normal curve start around hold position of 10%, and have to press the trainer button to initialize the ESC and each time I land and want to full soft start from the ESC?

Or is all of this moot and I should just run a low and high gov speed and setup normal to be, say, 0-20-20-20-20 and IDLE up at 90-90-90-90-90 and let the ESC govern to a low and high headspeed?

 

[coolgabsi]

OKay. Cool. Sounds like I'm in the ball park, maybe a bit aggressive. I'll back the setting off a click or two which should put me right around 9. Assigned my gyro switch to the banks and have a basic, sport, and 3D default setup going in banks 1-3 respectively. Will see how it all behaves after test flight and start dialing things in. My actual gyro channel is on the Ail DR switch.

One more issue to work out. Getting the castle ESC all set. It's in heli mode, so fixed endpoints. I played with it on the table (blades off). The 100% position seems just right. I have the auto-rotation bailout feature on, so there are two levels of 0 throttle. I'm finding the auto-rotation bailout off threshold kicks in around 13% throttle and full-off/reset signal kicks in around 8% throttle. So I set my hold curve up around 10 or 11 percent (so bailout is available). Normal curve is linear 0-100. Idle up is currently 90% across (haven't played with gov settings yet). I also assigned a throttle cut to the trainer button which is set at full negative setting (beyond even the low setting for the Ikon's throttle mapping), as a sort of backup in case its needed.

That all sound right?

My issue is that there is a lot of throttle stick movement before it starts doing anything while in normal mode. Would it be safe/reasonable to move the lowest point in the normal throttle curve up to say 6%? Or perhaps use the trainer as reset button and actually have the normal curve start around hold position of 10%, and have to press the trainer button to initialize the ESC and each time I land and want to full soft start from the ESC?

Or is all of this moot and I should just run a low and high gov speed and setup normal to be, say, 0-20-20-20-20 and IDLE up at 90-90-90-90-90 and let the ESC govern to a low and high headspeed?

Even if you are using castle governor , you will have to calibrate your esc end points with ikon. So that's what's needed before your throttle curves ... Your throttle curve will need to be linear for that.

Fly safe!! have fun!

 

[coolgabsi]

refer to this thread

Goblin Build... - Page 5

 

[pvolcko]

Cool, will give this a try. The basic 0-100 setup on the ikon seemed to produce ESC endpoints that were pretty close as is.

But all this is going to do is get rid of some ceiling and floor "headroom". What about the general issue of setting up hold for the auto-rotation bailout threshold vs the reset/off threshold?

 

[coolgabsi]

I haven't gotten into that auto rotation bailout in ikon. Helidirect has video on it. Check their YouTube


As for the headroom. That headroom was all the problem I had.. The esc was stuck in normal mode slow start, because the ikon sent 30 percent throttle and the esc thought I
Was still under 10 so it wouldn't fly at all as it would hang there at low headspeed and just jerk it's tail lol

Sort of scary with this size lol

Fly safe!! have fun!

 

[Island Breeze]

I haven't gotten into that auto rotation bailout in ikon. Helidirect has video on it. Check their YouTube


As for the headroom. That headroom was all the problem I had.. The esc was stuck in normal mode slow start, because the ikon sent 30 percent throttle and the esc thought I
Was still under 10 so it wouldn't fly at all as it would hang there at low headspeed and just jerk it's tail lol

Sort of scary with this size lol

Fly safe!! have fun!

Hmmm! I hope I don't run into that issue. What was your fix?

- - - Updated - - -

I haven't gotten into that auto rotation bailout in ikon. Helidirect has video on it. Check their YouTube


As for the headroom. That headroom was all the problem I had.. The esc was stuck in normal mode slow start, because the ikon sent 30 percent throttle and the esc thought I
Was still under 10 so it wouldn't fly at all as it would hang there at low headspeed and just jerk it's tail lol

Sort of scary with this size lol

Fly safe!! have fun!

Hmmm! I hope I don't run into that issue. What was your fix?

 

[coolgabsi]

You did what my fix was...


I installed hobbywing phase sensor for one as I was using the ikon governor

And I calibrated the throttle the correct way

Fly safe!! have fun!

 

[Tony]

Okay, this double posting is starting to worry me... Checking on the server...

 

[pvolcko]

Some more progress. Started cinching down zip ties. Modified ikon throttle outputs from 1000/2000 to 1050/1950ish using gaba's suggested method. Very little change in actual behavior (still kicks on around 20pct throttle). Also set up castle governor using 1700 for normal mode headspeed and 2050 for idle up. I also have 1900 available at 70pct throttle which I may try for idle up to start with. Should get some velcro straps delivered tomorrow and be able to maiden either late tomorrow or Thursday.

 

[Island Breeze]

Okay, this double posting is starting to worry me... Checking on the server...

I knew you would be on soon to check that...I may have fat fingered that, I was eating chicken at the time. LOL

- - - Updated - - -

Some more progress. Started cinching down zip ties. Modified ikon throttle outputs from 1000/2000 to 1050/1950ish using gaba's suggested method. Very little change in actual behavior (still kicks on around 20pct throttle). Also set up castle governor using 1700 for normal mode headspeed and 2050 for idle up. I also have 1900 available at 70pct throttle which I may try for idle up to start with. Should get some velcro straps delivered tomorrow and be able to maiden either late tomorrow or Thursday.

Can't wait to see the vid..

 

[pvolcko]

Flew it. Vid coming.

Got about a minute or two into things and ended up stripping out my main gear (CNC machined one at that). The pinion mesh was way too lose. I knew it, but I didn't have a good way to fix it. The motor mount is a KDE upgrade part and the prior owner (who will go nameless must have put the crazy monkey arm torque on it because one of the slide rails was deformed to the point I couldn't move the slider in the mount plate. If I put it in the frame one way the mesh was way too tight. No play at all, which I thought I read was bad for these machined gears since they build up heat and strip out. But put in the other way and it was too lose.

So I've ether got to get that slider moved a touch or buy a new mounting plate (or use the stock one).

I have two stock gears that I can use for now. No spare on the cnc machined one. No matter what I need to get this gear mesh issue worked out before I fly again.

So I'm grounded on this bird for the moment.

It flew nice for a couple minutes though.

 

[danhampson]

sorry to hear that, it sounds like quite an easy fix though. looking forward to the video.

 

[xokia]

Get the black gears. They are better anyway.

 

[pvolcko]

Okay, got the mount slider moved. Had to apply a little bit of rubber mallet to shift it. Got a good mesh now. Put one of the stock gears in. Waiting for LT to setup and need to redo one zip tie, pop some links back on and then spin up #2.

 

[Island Breeze]

Sweet..all sounds well for the next flight.

 

[coolgabsi]

Those are the CNC machined gears

 

[pvolcko]

And just to be clear, this was my fault. I'm not blaming "the prior owner". I knew it was a bad mesh, should have trusted myself.

 

[pvolcko]

Vids and rendering and uploading to youtube. In the meantime, some pics:

Closeup of the wiring and whatnot. Took me a while to figure out the strapping of the batteries at the nose. There is another strap on the back to prevent the pack from working backward too far. Nothing on the front since it is held in by the canopy pretty well and a lot of battery would have to work past the straps. I load and unload the battery tray from the back. Canopy posts get in the way trying to load or unload from the front. I'm not using a separate rx/fbl battery, running a caste bec pro mounted on the other side of the nose being fed by the full 12S voltage running along the lines below the gear assembly in this pic. Series EC5s soldered direct on the castle Ice2 120A HV ESC (the bec power taps are actually connected at a couple points were I took a square of insulator off the ESC leads and soldered on). Took a suggestion (or two) from Gaba and ran one motor connector outside the frame for easy disconnection (it is tough getting at the ones zip tied down inside the frame).



The wide shot. Very wide. This is a large heli. Rotor span has to be a bit over 4 ft. Body is a little under 4ft in length.



Need to do a bit more gyro gain tweaking, as you'll see in the second vid, but overall I'm pretty happy. I'm thinking of bumping the normal mode gov setting up to 1800 or 1850. 1700 seems a touch too slow. I also need to double check my gear ratio settings in the esc to make sure I'm not running artificially low.

Once I get the gyro/tail issue dialed out then I'll be ready to do some FFF with it and maybe a flip or roll or two. And test out the two other flight profile settings. All flight has been on the first setting I programmed in, and I'm finding the piro rate to be a bit slow at full stick.

Vids coming.